Grease a cake tin with butter on all the sides. Dust it with plain flour and sift to ensure uniform distribution of the flour.
Shake and tap the tin to remove the excess flour and keep aside.
Sieve the wheat flour, cocoa powder, baking powder, walnuts and soda in a deep bowl, mix well and keep aside.
Combine the sugar, milk, melted butter or oil, lemon juice, vanilla essence in a deep bowl and mix well.
Add the prepared sieved plain flour-cocoa mixture and approx.
mix gently with help of a spatula.
Pour the prepared cake batter into the greased and dusted tin and spread it evenly. Sprinkle choco chips.
Sprinkle the salt at the base of a pressure cooker, and place a steel ring stand and a perforated plate over it.
Cover it with a lid (with the ring on the lid but without the whistle) and heat on a medium for 5 minutes.
Open the lid of the pressure cooker, place the cake tin on the perforated plate.
Cover it with a lid (with the ring on the lid but without the whistle) and steam on a medium for 20 to 22 minutes or till the cake is done.
Allow the steam to escape before opening the lid. Keep aside to cool for 10 minutes.
Invert the tin over a wire rack and tap sharply to unmould the cake or use a knife to loosen the edges of the cake.
Use immediately or as required.
